Grinding-mill



(No Model.) 8

.G. A. YOUNG.

GRINDING MILL. No. 394,238. Patented Dec. 11, 1888.

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GEORGE A. YOUNG, OF BROOKLYN, NE YORK.

GRINDING-MILL.

SPECIFICATION forming part of Letters Patent No. 394,238, dated ecernber11,1888.

Application filed December 2, 1885. Serial No. 184,507. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE A. YOUNG, of Brooklyn, in Kings county andthe State of New York, have invented a certain new and usefulImprovement in Grinding-Mills, of which the following is aspecification.

My improvement is particularly intended for embodiment in mills whichare employed for grinding paint and analogous materials.

I will describe a grinding-mill embodying the improvement, and thenpoint out the various features of the improvement in the claim.

In the accompanying drawings, Figure 1 is a side elevation of agrinding-mill embodying my improvement, the upper portion being shown insection. Fig. 2 is an inverted view of the hopper and stationarygrinding-surface. Fig. 3 is a top view of the runner or rotarygrinding-surface.

The same letters of reference designate the same or corresponding partsin all the figures.

A designates the main frame of the machine. It is preferably cast in oneintegral piece. As shown, it consists, essentially, of three legssupporting a plate provided with a spout or chute and a holder for thehopper B.

The hopper B may be made of cast metal. It is of circular form andtapers or decreases in size downwardly. At the lower edge it has aninwardly and outwardly extending flange, b, which rests upon and issupported by the frame A. The under surface of the flange Z7 constitutesthe stationary grinding-surface of the mill. It is inclined upwardlyfrom the outer to the inner circumference, and has formed in it a seriesof grooves which are deeper at the inner circumference than at the.outer circumference of the flange. These grooves are not radiallyarranged, but are arranged so as to be tangential to a circle ofsomewhat smaller diameter than the inner circumference of the flange.

O designates the runner or rotary grinding surface or part of the mill.Its under side may beflat or concave, or of any appropriate shape, andmay be provided with a hub for fitting upon the shaft or spindle D, bywhich it is carried, and with a number of radial strengthening-ribs. Itsupper surface is composed of an outer rim or flange-like portion, 0,which is elevated above the central portion, 0, which it surrounds, andprovided with a series of grooves that are approximately tangential to acircle smaller than the inner diameter of this portion and deeper at theinner than at the outer circumference. This outer rim or flange-likeportion has its upper surface inclined upwardly from the outer to theinner circumference. Its incline should approximately correspond withthe incline of the lower surface of the flange b, belonging to thehopper B.

The central portion, 0, of the runner O is convex, being much higher atthe center than at its junction with the rim or flange-like portion 0.

The spindle D, which carries the runner, passes through a bevelgear-wheel, E, that is supported upon an arm or bracket, A, arrangedbetween the legs of the frame A. The spindle is connected to this bevelgear-wheel by means of a groove and spline, so that it will deriverotary motion from said gear-wheel and be capable of being elevated orlowered without affecting the position of the said gearwheel. Thespindle D at the lower end rests in a step-bearing provided in anadjustable arm, G. This arm G is hung at one end upon a bracket, H,relatively to which it may be swung as upon a fulcrum, and is fastenedat the other end to a screw, I, that has applied to it above the bracketA a nut and handwheel, I, which may be adjusted at pleasure. Byadjusting this hand-wheel the spindle D, and consequently the runner O,carried by it, may be raised and lowered at will.

The bevel gear-wheel E engages with a pinion, G, which is aifixed to ahorizontal shaft, K, that is provided with fast and loose pulleys L L,and journaled at one end in a portion of the frame A and at the otherend in an extension, A of the frame A.

The extension A may be made separately from the frame A and securedthereto by screw-bolts.

The construction of the runner C is of great importance. The differencein elevation be tween the outer rim or flange-like portion, 0, and thecentral portion, 0, insures a grindingsurface for the runner of uniformwidth, even after wear and repeated dressings, for in dressing thisgrinding-surface the grooves will not be elongated beyond their originaldimensions, as is inevitably the case where the grinding-surfaceoriginally made and the central portion of the runner or flange areflush. This uniformity in the grinding-surface is of great importance,because the machine is more uniform in its action than it otherwisewould be, and the labor of dressing and re-dressing the grinding surfaceis materially reduced,'because the grooves never become prolonged beyondtheir original dimensions by re-dressing them.

The protuberance or convexity of the central portion, 0', causes allhard substances to gravitate to the lowest portion, which is at thejunction of such central portion, 0, with the rim or flange-like portion0.

Any pieces of metal or other extraneous or hard substances, which arealways to be found in paint and like materials to be ground, will becomeseparated from the paint and gravitate down to the junction of thecentral portion of the runner with the rim or flange-like portion, andwill be retained there, so that they cannot pass between thegrinding-surfaces with the paint or like material. The in jury which thegrinding-surfaces of mills commonly sustain by reason of the passage ofsuch hard substances between them or through them is obviated. I alsoavoid by means of tween them, and theconsequent loss of the paint orother valuable material which is allowed to pass freely through thespace between the grinding-surfaces at the time, and by its centrifugalforce is thrown around the place where the mill is located.

YVhat I claim as my invention, and desire to secure by Letters Patent,is- In a grinding-mill, the combination, with an upper grinding-surfaceinclining upwardly from its outer to its inner circumference, of arunner arranged below the same and having on its upper surface anelevated rim or flangelike portion provided with a grinding-surfaceinclining upwardly from its outer to its inner circumference, and acentral portion which is convex and lowest at its junction with the rimor flange-like portion, substantially as speci fied.

GEORGE. A. YOUNG. Vitnesses:

EDWIN H. BROWN, DANIEL H..DR1sooLL.

